A thermoactive α-amylase from a Bacillus sp isolated from CSMCRI salt farm

Amylases are the most important hydrolytic enzymes for starch-based industries. It is desirable that alpha-amylases should be active at high temperature of gelatinization (100-110 degrees C) and liquefaction (80-90 degrees C) to economize processes. Therefore, thermostable and thermoactive enzyme from natural bacterial strain would have wide industrial importance. In the present study a highly thermoactive and thermostable amylase producing Bacillus sp. was isolated from experimental salt farm of Central Salt and Marine Chemicals Research Institute, yielding 452 U ml(-1) amylase in medium containing (%) NaCl 0.5, peptone 0.5, beef extract 0.3, starch 1.0 at 37 degrees C, pH 7.0 after 48 h of incubation. Maximum activity of amylase was observed at pH 8.0 and 110 degrees C temperature. The crude enzyme was highly active between pH 6.0 and 11.0 and observed to be active and thermostable after 30 min of incubation at 60 degrees C. These properties indicated that the isolated alpha-amylase enzyme is suitable for starch liquefaction and other food processing. (C) 2010 Elsevier B.V. All rights reserved.